1. Field of the Invention
The present invention relates to a look-up device, and more particularly to a device conformed in the manner of a slide rule for correlating the call letters of a station with the frequency thereof.
2. Description of the Prior Art
In ham radio operations and in selecting a particular radio station for listening, very often the user either knows the frequency at which the station is to be selected, or the call letters, but very rarely does he know both. Generally the band width required for transmission varies logarithmically with the particular center frequency. Thus, as a particular wavelength is selected the density of the stations adjacent thereto varies according to the wavelength. Most often the tuning display of a radio will combine several frequency bands and a display of both the frequency and the call letters of a station thus is often impractical. Accordingly, a user who recollects either the frequency or the call letters cannot conveniently cross correlate between two pieces of information from the visual display on the tuning dial.